What is the best service for mass emailing through your website?

Does anyone have recommendations on the best service for providing mass emails from your website? I do not mean newsletter type of email blasts from Constant Contact or Mail Chimp. We have many thousands of users signed up as members of our social network and we want to send them email alerts every time an user follows another user and other actions happen within the platform. This generates a considerable amount of email alerts that are sent out, and the site is growing quickly. So, we are in need of a mail service that will do this for us and make sure our site does not get blacklisted.

We've used sendgrid for our transactional emails. They go to a lot of effort to ensure that email is delivered. They provide a host of important features like the ability track delivery, handle being reported as spam -- yes, your customers will do this!

The API is easy to use and has a lot of features you can add to improve the user experience.

I used MailChimp for 6 months, but it's pricey if you've got tens of thousands of addresses.

I use SendGrid for transactional emails, and a few months ago they added marketing email features - and it's FAR less expensive. Yes, they haven't got all the features figured out yet, but for the cost savings, it was worth it to me.

MailChimp lets you put your account on 'hold', which I did, and I've now sent several campaigns through SendGrid.

For MailChimp, I was paying $300+/mnth to store and 'manage' the email addresses.

For SendGrid, I'm paying $10 per 10,000 email addresses, and when I send campaigns, each message sent comes out of my monthly plan.

Overall, I'm saving several hundred dollars a month, with limited loss of features.

For transactional emails, I have used SMTP.com and Sendgrid.com . Performance is comparable as both gives yu tools to manage the IP reputation and abuse management. SMTP.com is slightly cheaper for transactional mails at larger quantities.

Regarding your specific use case, we have webhooks which you can integrate with your platform and send the email through our platform. You can even set various rules and triggers to decide when to trigger an email to your users. The biggest plus point: Minimal developer effort required from your end.

Please reply if this interests you and I can hop on a call with you to explain more about our product.

What you'll quickly find is that sending out an email everytime someone does something will make people unhappy really quickly. Learned the hard way you need to give people ability to opt out of certain notifications and filter/throttle/journal notifications to individual users so you don't have people unsubscribing due to noise.